Rum Procedure Advice

[gundog48]

I was wondering if you'd take a look at my rum procedure and tell me what you think, I'm trying to produce something with some decent esters, but I'm looking for a fairly straightforward procedure. I've had problems in the past with stuck fermentations and pH crashing, which I'm hoping to deal with.

The wash:

Distillmax RM
1Kg Sugar for every 5Kg Molasses (should be equivilent to high test molasses)
0.05g/L DAP
0.015g/L Epsom Salts
Start at 10°B, then adding 2 more additions every 10 hours to target 10% ABV
Ferment at 32°C

Handling Dunder
Dunder will be added in lieu of water at a rate of 20% on the second fermentation (I don't have any for the first!) And 10% on subsequent batches.

The dunder will be removed from the still and I will add calcium hydroxide to achive a pH of 4-4.5, I am relying on this to buffer my fermentations.

It will typically go in fresh, but may be stored between 'campaigns'

Stripping Run

Charge the wash. If the pH is above around 3.5, adjust down with 80% lactic acid. I'm worried that the CaOH in the dunder will keep all my acids locked up as salts, so I want to make sure they are properly liberated. Maybe I'll use sulphuric?

I will run the distillation hard towards the end to collect as much of the volatile acids and any esters as possible.

Spirit Run

Add a small amount of sulphuric acid to the low wines to encourage esterification. Unsure exactly how much, shouldn't need much, probably aim for a pH of 3-4. May get my chemist friend to do a titration on the low wines! Will run under full reflux for 30 mins to an hour, then collect under a small amount of reflux, hopefully getting a heart cut around 80%ABV.

Would love to know your thoughts, specifically around nutrition and buffering. I've not heard of people specifically using ph-adjusted dunder to buffer their fermentations. I really don't like adjusting fermentation pH on the fly, so this sounds like a good way forward for me.

[8Ball]

Sounds interesting. If you can get ahold of it, I’d use panela instead of plain sugar. I’ve had very good results using a 1.7/1.0 panela /molasses ratio. As for your starting pH, yours is high compared to what I’ve had success with — my washes start around ph 4.85 using 15% fresh dunder by volume. Use a couple of good handfuls of clean, crushed oyster shells at the start of the ferment to keep the ph buffered. I use a combination of plain bread yeast and FermPro 921 at 2g/G. The ferment runs hot and finishes in a little over a week, sometimes sooner. Strip and 1.5 spirit (low wines, feints, and a little fresh wash) with good cuts using a copper pot. Age on used white oak for as long as you can.

[NZChris]

I was wondering if you'd take a look at my rum procedure and tell me what you think, I'm trying to produce something with some decent esters, but I'm looking for a fairly straightforward procedure. I've had problems in the past with stuck fermentations and pH crashing, which I'm hoping to deal with.

The wash:

Distillmax RM The worst rum ferment I ever made was using this yeast. Bread yeast gets me good results every time
1Kg Sugar for every 5Kg Molasses (should be equivilent to high test molasses)
0.05g/L DAP
0.015g/L Epsom Salts Why? I've made all of my rum without it.
Start at 10°B, then adding 2 more additions every 10 hours to target 10% ABV
Ferment at 32°C

Handling Dunder
Dunder will be added in lieu of water at a rate of 20% on the second fermentation (I don't have any for the first!) And 10% on subsequent batches.

The dunder will be removed from the still and I will add calcium hydroxide to achive a pH of 4-4.5, I am relying on this to buffer my fermentations.
I doubt it will act as a buffer.
It will typically go in fresh, but may be stored between 'campaigns'

Stripping Run

Charge the wash. If the pH is above around 3.5, adjust down with 80% lactic acid. I'm worried that the CaOH in the dunder will keep all my acids locked up as salts, so I want to make sure they are properly liberated. Maybe I'll use sulphuric?
Only adjust pH if you have to. You should worry about locking up the acids at this point, as you want esters in your low wines, not acid salts in your backset. I don't know why you would use lactic acid if you have sulfuric available.

I will run the distillation hard towards the end to collect as much of the volatile acids and any esters as possible.

Spirit Run

Add a small amount of sulphuric acid to the low wines to encourage esterification. Unsure exactly how much, shouldn't need much, probably aim for a pH of 3-4. May get my chemist friend to do a titration on the low wines! Will run under full reflux for 30 mins to an hour, then collect under a small amount of reflux, hopefully getting a heart cut around 80%ABV.

Would love to know your thoughts, specifically around nutrition and buffering. I've not heard of people specifically using ph-adjusted dunder to buffer their fermentations. I really don't like adjusting fermentation pH on the fly, so this sounds like a good way forward for me.

I use large whole sea shells in a bag as they behave like a buffer and can easily be removed if pH starts creeping too high because you used too much, or the ferment is finished.

[zapata]

I think a lot of us with muck pits do something to keep the pH in check. I know I do, when it gets too acidic the bacteria die and I bump it back up to 5-6 typically with calcium hydroxide to keep it alive. This is fairly proven and there isn't much worry about locking acids up as salts. Remember there is a huge difference between pH and total acids.

Also remember that very few salts exist as such in a solution. Salt solutions overwhelmingly consist of the ions floating about freely, in this case where the acids will be free to form esters. And even if you do have un-disolved salts, pretty much as soon as one acid molecule esterifies a salt molecule will ionize and dissolve to replace it. The same thing will happen while stripping when one ester or acid molecule distills over, the equilibrium will favor replacing it if possible.

I think your plan is solid, if a little over-thought. I have used epsom in many a rum wash, can't say it's absolutely needed but at worst it can't hurt. But if you aren't buffering the dunder to cultivate bacteria, I don't know why you would bother. It seems your only reason to do that is as a roundabout way to buffer the wash pH, but as Chris points out that's much easier and more directly done with oyster shells or marble chips straight in the wash.

[NZChris]

Culturing desirable bacteria in a dunder pit and putting slaked lime in fresh dunder in the hope that the dunder will behave as a buffer in the next generation are very different ideas and I'm suspecting only one of them has any chance of a desirable outcome.

[Oldvine Zin]

Distillmax RM The worst rum ferment I ever made was using this yeast.

I agree with NZChris

Stay safe
OVZ

[SaltyStaves]

Distillmax RM The worst rum ferment I ever made was using this yeast.

It has been responsible for both the best and worst for me. I swore off using it ever again after it ruined some high grade molasses.
Its a shame because it was great when it worked well.

[Oldvine Zin]

Distillmax RM The worst rum ferment I ever made was using this yeast.

It has been responsible for both the best and worst for me. I swore off using it ever again after it ruined some high grade molasses.
Its a shame because it was great when it worked well.

Ive just only had the bad with this yeast. My current batch I'm experimenting with white Labs Horindal Kveik yeast, so far so good but slower than what I had expected. Smells great and not that stink that I got with the RM

Stay safe
OVZ

[RūmHôk]

https://biotechnologyforbiofuels.biomed ... 017-0701-8


Found this very interesting read.
Some points that pertain to our collective endeavour over here.